The merger of Marathon Petroleum Corp. (NYSE: MPC) and Andeavor Corp. (NYSE: ANDV) announced before the opening bell April 30 creates a new U.S. energy colossus with significant midstream, refining and marketing assets. Both companies exited upstream operations in years past.

The two companies have assets that stretch from the Atlantic to Alaska. Antitrust questions may not be an issue as the two have little geographic or marketing overlap. Marathon’s operations are predominantly in the Midwest and Southeast while Andeavor’s focus is the upper Midwest and west of the Rockies.